A spectacle lens is fabricated by edging an uncut circular lens into a round shape based on the rim shape data of a spectacle frame by an edging device. In the edging, a bevel (V-shaped projection) to be inserted in the bevel groove (V-shaped groove) in the spectacle frame is formed on the edge surface of the spectacle lens. After the round spectacle lens is fabricated, the perimeter and shape of the bevel vertex are three-dimensionally measured by a bevel perimeter measurement apparatus disclosed in, for example, Japanese Patent Laid-Open No. 2000-74656 or 06-175087 to examine whether the spectacle lens precisely conforms to the rim shape of the spectacle frame.
In measuring the bevel by the bevel perimeter measurement apparatus, the beveled spectacle lens has its center held from above and below in an almost horizontal state by a lens holding means to engage a V-shaped groove formed in a stylus (measurement unit) with the bevel. Next, in this state, the stylus is moved along the bevel vertex, and the rotation angle, a horizontal displacement, and a vertical displacement of the stylus from a reference point for the stylus or lens are measured by a rotation angle measurement device, horizontal displacement measurement device, and vertical displacement measurement device, respectively. Based on these measured values (θ, r, z), the perimeter and shape of the bevel vertex of the edged spectacle lens are calculated by a perimeter calculation means. Lastly, the calculated perimeter and shape are compared with the rim shape data of the spectacle frame to determine whether the lens meets edging evaluation criteria.